Möbius ladder

Summary

In graph theory, the Möbius ladder $M_{n}$, for even numbers $n$, is formed from an $n$-cycle by adding edges (called "rungs") connecting opposite pairs of vertices in the cycle. It is a cubic, circulant graph, so-named because (with the exception of $M_{6}$ (the utility graph $K_{3,3}$), $M_{n}$ has exactly $n/2$ four-cycles which link together by their shared edges to form a topological Möbius strip. Möbius ladders were named and first studied by (txt).